interstitial granuloma annulare
Synopsis
assessed under low power
increased number of inflammatory cells in the dermis separated by connective tissue mucin
inflammatory infiltrate composed of lymphocytes and histiocytes
inflammatory cells around blood vessels and between collagen bundles.
no well-defined areas of necrobiosis
Differential diagnosis
interstitial granulomatous drug reaction
- eosinophils (+)
- lichenoid changes at dermoepidermal junction
- true necrobiosis rarely noted
interstitial granulomatous dermatitis
- neutrophils and neutrophil fragments
- histiocytes, lymphocytes & eosinophils
- palisades of histiocytes around basophilic collagen fibres